1997 code Y motor.
At the end of the intake manifold next to the power steering pump (opposite end from the throttle body), is a large flapper thingy that opens directly into the intake. It's spring loaded closed. What is it, and what's its purpose? Looks like a toilet tank flapper valve.

JimD

12-16-05, 02:47 PM

That is a relief valve to prevent positive pressure damage to the non-metallic manifold as in the case of a "backfire".

Ranger

12-16-05, 06:59 PM

Auxilliary throttle plate :histeric:

ewill3rd

12-16-05, 07:23 PM

It's called a "backfire valve" it pops open in the event of a backfire so the intake doesn't explode.
Guess how they figured out that it needed to be there?
:D

AlBundy

12-16-05, 11:20 PM

They figured out that it might be easier to give out burp instead of giving out a stinkie FART?

ewill3rd

12-17-05, 10:37 AM

We also had problems on some 3800's back in the 90's with exploding intakes. They issued a software update for the PCM to fix that concern though.
Not sure if I can find any pictures but I have seen some.

Ranger

12-17-05, 01:42 PM

We also had problems on some 3800's back in the 90's with exploding intakes. They issued a software update for the PCM to fix that concern though.
Not sure if I can find any pictures but I have seen some.
I remember hearing about that when I did some research prior to replacing the intake on my wifes '96 Bonnevile (not for that reason).

CadillacSTS42005

12-17-05, 02:03 PM

exploding intakes are fun especally when you do a wet nos system and it pools in the intake then KABOOMY!!!!!!!